Horde_Kolab_Format_Xml_Helper::findNode PHP Method

    public function findNode($query)
    {
        $result = $this->_xpath->query($query);
        if ($result->length) {
            return $result->item(0);
        }
        return false;
    }

 /**
  * Update the specified attribute.
  *
  * @param string                        $name        The name of the the
  *                                                   attribute to be updated.
  * @param array                         $attributes  The data array that holds
  *                                                   all attribute values.
  * @param DOMNode                       $parent_node The parent node of the
  *                                                   node that should be
  *                                                   updated.
  * @param Horde_Kolab_Format_Xml_Helper $helper      A XML helper instance.
  * @param array                         $params      Additional parameters
  *                                                   for this write operation.
  *
  * @return DOMNode|boolean The new/updated child node or false if this
  *                         failed.
  *
  * @throws Horde_Kolab_Format_Exception If converting the data to XML failed.
  */
 public function save($name, $attributes, $parent_node, Horde_Kolab_Format_Xml_Helper $helper, $params = array())
 {
     if (!($root = $helper->findNode('/' . $name, $parent_node))) {
         $root = $helper->createNewNode($parent_node, $name);
         $root->setAttribute('version', $params['expected-version']);
     } else {
         if (!$this->isRelaxed($params)) {
             if (version_compare($params['expected-version'], $root->getAttribute('version')) < 0) {
                 throw new Horde_Kolab_Format_Exception_InvalidRoot(sprintf('Not attempting to overwrite higher root version of %s with our version %s!', $root->getAttribute('version'), $params['expected-version']));
             }
         }
         if ($params['expected-version'] != $root->getAttribute('version')) {
             $root->setAttribute('version', $params['expected-version']);
         }
     }
     $this->_prepareCompositeParameters($params, $params['expected-version']);
     parent::save($name, $attributes, $parent_node, $helper, $params);
     return $root;
 }